(1) Field of the Invention
The present invention relates to insoluble lead or lead alloy electrode, and more particularly the invention is to provide insoluble lead or lead alloy electrode for electroplating, which is excellent in energy efficiency and easy to regenerate through repair.
(2) Description of the Prior Art
At present, there have widely been used the electrodes made of lead or a lead alloy such as Pb-Sn, Pb-Sb or the like as an insoluble electrode for use in electroplating with zinc, chromium or the like. In the electrodes of this type, although only substantially one side of the electrode is required as discharging face, from the standpoint of corrosion resistance, there has been used an electrode which is entirely made of lead or the lead alloy, or the one wherein the whole side surfaces of a core member of the electrode plate are subjected to a lead homogenizing treatment.
However, in the above electrode, since it is structurally impossible to prevent the occurrence of the wasteful electric discharge from the backside of the electrode, the current efficiency is disadvantageously poor. Further, since the dissolving amount of lead is larger, there is also disadvantage that an area of the lead pollution becomes wider. In addition, in case the wear-out electrode is regenerated through repair, it is necessary to make a lead build-up upon the whole surface of the electrode, so that there are various kinds of problems, for example, that it takes not a short time to repair the electrode plate and at the same time it becomes costly to repair.
As the countermeasures for preventing the occurrence of the wasteful electric discharge, that is, the stay current, from the backside of the electrode, it has been proposed that an electric insulating lining of, for instance, resin, rubber or the like, is formed on the backside surface of the electrode plate. But, such a proposal is not free from the defects that a superfluous step in the repair-regeneration is required with an increased manufacturing cost.